What is the best bang for your buck when it comes to shooting .22 LR shells in the 422. i.e best for not jamming.

Rimfire guns can be extremely picky about ammo. I know .22 LR can be difficult to find, and costly when you find it, but you need to try as many different brands as possible to see what your particular gun likes.

I have owned nine of the 422/622/2206/2213/2214 handguns and still own four. They all liked ammo such as CCI Mini Mags and equivalent types. I had one that would shoot and feed Remington HS .22 Longs, another that worked perfectly with Aquila SS.

If you find something that works well, try to buy as much of that brand and lot number that you can.

My own 422 feeds just about everything well. IMHO the easiest route to go concerning ammo would be to stay with high speed long rifles that have a sharper taper (ogive) to the bullet nose. CCI blazer HS has a sharp tapered ogive as do several of the least expensive federal promo products sold in "Bulk" packs at outlets such as Wally World. Be sure to to keep the breech face and feed ramp/chamber area of your pistol clean. Very important for reliable feeding. I dry scrub my 422 after each range session with a stiff bristled tooth brush. Takes all of 30 seconds.

Anyone successfully shooting Winchester wildcats or Remington thunderbolts?